Iron is an essential mineral, trace element involved in electron transport and numerous enzymatic redox reactions that take place in the body, such as oxidative phosphorylation that provides the body with energy. Iron also forms the essential heme prosthetic group of hemoglobin, that makes oxygen transport by red blood cells possible, and of myoglobin, that allows muscle cells to store oxygen for utilization. Without sufficient iron, mammalian life is just not possible. Iron present in the body beyond what is immediately needed for functional purposes is stored. Too much iron can cause iron overload that results in iron-mediated oxidative stress damage to cells and organs. Too little iron can cause an iron deficiency, and if prolonged, results in iron deficiency anemia as ferritin cellular iron stores are depleted followed by transferrin transport iron. This depleted state reduces red blood cell production and leads to unhealthy, small and pale, red blood cells. For these reasons, iron homeostasis is generally well regulated in the body, and in healthy individuals, iron recycling is very efficient. However, unhealthy individuals and different circumstances and illnesses can lead to much greater iron loss. Conditions that can lead to iron deficiency include malnutrition, iron absorption or retention disorders, irritable bowel syndrome, as well as, pregnancy, blood loss, such as from menses, medication induced intestinal bleeding, such as from aspirin and other nonsteroidal anti-inflammatory drugs, NSAIDs, gastric ulcers, and parasitic gastrointestinal infections.
Regulation of iron balance occurs mainly in the gastrointestinal tract through absorption. This absorptive process is both regulated and inefficient, to prevent the excess intake of iron. When diet alone cannot maintain or restore deficient iron levels, iron supplementation is often necessary. Oral iron preparations have been used medicinally for many centuries. It has been fabled that oral iron has been used in antiquity, as early as 4000 B.C., to treat hemorrhagic losses in wounded Persian soldiers. In the modern era of medicine, French physician P. Blaud de Beaucaire is credited with administration of iron pills to treat anemia circa 1831. Advertisements for the sale of pharmaceutical preparations of ferrous iron appeared in United States medical journals as early as 1850. The medicinal uses of iron as a treatment for iron deficiency anemia, and how oral iron administration induces increased red blood cell formation in these patients as a hematinic agent, have been detailed in encyclopedias since 1900, and proven in clinical studies over the last century.
There are various forms of iron that have been provided as oral supplements. These include both the ferrous iron and ferric iron forms, most often as iron salts, e.g., ferric sulfate, ferrous sulfate, ferrous fumarate, ferrous gluconate, and sodium ferric gluconate. Further oral iron examples include iron amino chelate, iron polymaltose complex, carbonyl iron, and heme derived iron. These various forms of iron have different compound weights. Furthermore, various forms of iron can be anhydrous, or exist in one or more different hydration states, each having their own weight. For example, ferrous sulfate has five different hydration states in addition to the anhydrous form. Therefore, when referring to various iron formulations, it is often necessary to standardize the iron content in the form of an elemental iron equivalent content. For instance, 200 mg of ferrous sulfate, depending on its hydration state, often contains approximately 65 mg of elemental iron equivalent.
The prior art shows various multivitamin tablet configurations, including iron tablets having an enteric coating, tablets composed of a slow and fast release formulation of iron, and tablets with an iron core. However, none of the prior art describes or teaches a solid oral formulation including a tablet core surrounded by an iron sugar overcoat so that the iron sugar overcoat makes at least some elemental iron content available for gastrointestinal absorption relative to the tablet core while counteracting at least some of the constipation associated with oral iron consumption. The tablet core includes at least one therapeutic ingredient. This tablet core is surrounded by an iron sugar overcoat. The iron sugar overcoat includes at least one form of bioavailable iron and at least one sugar. This iron sugar overcoat makes available at least some elemental iron content for gastrointestinal absorption either prior to the release of the at least one therapeutic ingredient of the tablet core, or concomitant to the release and absorption of the at least one therapeutic ingredient of the tablet core. In this sense, the relative release and absorption of iron from the iron sugar overcoat is controlled relative to the release and absorption of the at least one therapeutic ingredient of the tablet core. Iron transporters of the intestines can be primed with iron prior to the absorption of the at least one therapeutic ingredient of the tablet core. The iron sugar overcoat, and any iron contained in the core, can help reduce gastrointestinal bleeding, help maintain iron levels in the body, or help replenish iron levels in the body. Therefore, the solid oral formulation can therefore help prevent or treat iron deficiency or iron deficiency anemia. In one embodiment of the invention, the sugar overcoat provides at least some iron to counteract the iron loss due to gastrointestinal bleeding caused by NSAIDs, and as a styptic, antihemorrhagic agent, e.g., ferric sulfate or ferrous sulfate, reduce gastrointestinal bleeding. As such, this embodiment may contain an NSAID core. In another embodiment of the invention, the sugar overcoat provides at least some iron to counteract the iron loss associated with irritable bowel syndrome, IBS, and can help treat its symptoms. As such, this embodiment may contain an IBS drug core, e.g., dicyclomine, an anticholinergic. Importantly, the at least one sugar of said iron sugar overcoat is what has some laxative effect that counteracts at least some of the constipation associated with oral iron consumption. Many other beneficial therapeutic ingredients can be envisioned for the solid oral formulations according to this invention.